Apparatus for conducting sintered material from a sintering grate to a cooling grate



Nov. 3, 1964 BERG ETAL 3,155,378

APPARATUS FOR counucmc SINTERED MATERIAL FROM A SINTERING GRATE TO A COOLING GRATE Filed Dec. 1, 1961 2 Sheets-Sheet 1 INVENTORs LEO BERG JOSFFMCHJEZE'HW AZFBED SGHOLZ L. BERG ETAL Nov. 3, 1964 3,155,378 APPARATUS FOR CONDUCTING SINTERED MATERIAL FROM A SINTERING GRATE TO A COOLING GRATE 2 Sheets-Sheet 2 Filed Dec. 1, 1961 Josef vachrqmer' Aural Sckb'ZL Br 6, 2 f d United States Patent APPARATUS FOR CONDUCTING SENTERED MA- TERIAL FROM A SINTERING GRATE TO A COOLlNG GRATE Leo Berg, Hurth-Altstatten, .Tosef Nachreiner, Gleuel,

near Cologne, and Alfred Schiill, Cologne-S1112, Germany, assignors to Knapsack-Griesheim Aktiengeselischaft, Knapsaclk, near Cologne, Germany, a corporation of Germany Filed Dec. 1, 1961, Ser. No. 156,262 Claims priority, application Germany Dec. 1, 1%0 5 Ciaims. (Cl. 263--8) The present invention relates to an apparatus for conveying hot sintered material'from a sintering grate to a cooling grate positioned beyond the sintering grate.

The hot sintered material is usually thrown off from a chain type travelling grate (Lepol grate) by way of socalled stripping plates, one edge of which is pivotally mounted upon the chain of the grate. The said stripping plates serve to conduct the sintered material which has been stripped otf and to constitute a heat insulation for the returning strand of the chain. They fulfill these tasks, however, in an unsatisfactory degree only, since they are lifted up again and again by sintered material which has been jammed in, and due to this fact a large quantity of sintered material falls through the chain of the grate, and the returning strand of the chain is endangered by hot gases flowing through. In addition, the lowest layer of sintered material which lies immediately on the sintering grate is pressed against the longitudinal edges of the stripping plates and is partly crushed. This results in an increase of the portion of abraded material.

In the cement industry, for example, one has endeavoured to overcome the aforesaid difficulties by conducting the whole of the layer of clinkers lying on the sintering grate over a layer of clinkers which rests immovable due to the arrangement of stripping plates provided with sills and being mounted at a low level, and by then causing the first-mentioned layer of clinkers to be thrown off in free fall. This Way of operating enables a useful heat insulation of the returning strand of the sintering grate to be obtained, but the degree of abrasion of the lowest layer of clinkers, the burning of which has not yet been terminated is considerably increased. additional expenditure for the removal and the re-use of the sintered material falling through at the throweofi place and the material which has been abraded is required.

In contradistinction to the known arrangements, in the apparatus according to the present invention, the sprocket of the cooling grate arranged beyond the sintering grate is installed approximately vertically below the driving sprocket of the sintering grate. In order to prevent the plates of the grate from pivoting too early when passing through the circular are on which they throw the sintered material, the grate plates are flanked by guiding ribs which are supported by angle plates arranged at a low level. Before the lower edge of the angle plates an inclined plane is arranged whichreaches approximately to the surface of the cooling grate and which serves as slide way for the sintered material thrown off from the sintering grate and, following the said guiding ribs, a slide bar serving to guide the grate plates is arranged below the returning strand of the sintering grate. Below the grate plates which after leaving the slide bar pivot downwardly to hang freely, an inclined plane over which the residual portion of the sintered material falling off from the freely hanging grate plates slides to the cooling grate is arranged outside the suction chamber of the sintering grate.

The slide bar serving to guide the grate plates of the returning strand of the sintering grate can be adjusted.

The concave surface of the angle plates supporting the guide ribs faces the cooling grate.

Moreover, a

3,155,378 Patented Nov. 3, 1964 The inclined plane arranged for conveying the bulk of the sintered material thrown off from the sintering grate is shifted in the direction in which the cooling grate moves and the second inclined plane serving for conveying the residual portion of the sintered material is arranged above the return sprocket of the cooling grate.

The upper edge of the inclined plane serving as slide way for the sintered material thrown off from the sintering grate is located at a higher level than the lower horizontal inside of the angle plates.

Apparatus embodying the invention will now be described in greater detail by way of example only with reference to the accompanying drawings of which:

FIG. 1 is a top view of the apparatus of the'present invention; and

FIG. 2 is a longitudinal section of the apparatus according to the invention.

In the apparatus according to the invention shown in FIGS. 1 and 2 grate chain 1 of the sintering grate runs in the direction of the arrow over driving sprocket 5. Pivotally mounted grate plates '7 on chain 1 are held in place by guide ribs 18 beginning at the place at which they might pivot downwardly in view of their own weight and are then conducted in the returning deck of grate chain 1 by slide rail 16 until they hang freely, slide rail 16 being hinged and being adjustable to the most favorable inclined position by a mechanical device 17.

In the apparatus according to FIGS. 1 and 2, sintered material 15 is not stripped off but falls freely from grate plates '7 onto angle plates 19 from where it glides and rolls over inclined plane 22 onto grate chain 2 of the cooling grate which moves in the direction of the arrow and is conducted over return sprocket 3.

Angle plates 19 are formed each of a horizontal leg arranged at a low position and a vertical leg arranged in a right angle to the horizontal leg, the upper part of the vertical leg being'bent backward, so that the upper edge is as near as possible to grate plates 7. Guide ribs 18 for grate plates 7 are fixed to angle plates 19. The concave side of angle plates 19 faces the cooling grate. Sintered material 15 thrown off from grate chain 1 of the sintering grate onto angle plates 19 first accumulates on the angle plates and this accumulation Zti substantially remains at the place where it has formed. The formation of accumulation 20 is favoured by the fact that the upper edge of inclined plane 22 is situated at a higher level than the lower horizontal inner surface of angle plate 19.

In order to enable the small portions of sintered material 15 which are not thrown off via angle plctes 19 but fall through between angle plates 19 and grate plates 7 or which first adhere to tilting grate plates 7 and then fall down, to be also seized in a simple and reliable manner, the sintering grate and the cooling grate are arranged in such a manner that the discharge end of the sintering grate and the receiving end of the cooling grate are mounted approximately vertically one above the other. Besides, below hinged grate plate 7 an inclined plane 21 is arranged which reaches from opening 25 through which grate plates 7 pass and which is located in front wall 24 of suction chamber 23 arranged below the sintering grate and described in commonly assigned US. patent application Serial No. 82,091 filed on January 11, 1961, in the name of W. Bielenberg et al. for Process and Apparatus for the Drying and Burning of Pellets, now US. Patent 3,100,106 to above a grate chain 2 of the cooling grate which, after having encircled return sprocket 3, is again drawn in a horizontal position. A consequence of these measures is that the sintered material falling through directly as well as sintered material 13 which is first entrained by grate plates 7 and then falls down drops onto grate chain 2 of the cooling grate either immediately in free fall or via inclined plane 21.

In the apparatus described above the axes of driving sprocket 5 of the sintering grate and of return sprocket 3 of the cooling grate does not require a vertical alignment one above the other in the strictly geometrical sense. Deviations from the vertical arrangement of the axes are admissible as long as it is ensured that the portions 13 of sintered material falls onto the tight strand of grate chain 2 of the cooling grate, which strand is drawn in a horizontal direction.

Inclined planes 2.1 and 22 are formed in known manner of an iron frame work nogged with refractory masonry.

For the purpose of introducing cooling air to grate plates 7 of the sintering grate which are being freed from hot sintered material driving sprocket 5 is provided with a special device 6 serving to conduct said cooling air.

Grate plates 7 of the sintering grate which are capable of turning about and then pivoting to hang freely are also cooled by cooling air which according to the above-mentioned specification is present under superatmospheric pressure illustrated as chamber 26 in FIG. 2 under the cooling grate and parts of which penetrate through the openings of the grate plates of the cooling grate which at that moment carry a 'weak load only into the space .dispensed with. Hence, there is no more danger that grate plates 7 jam or break at stripping plates, so that the sintering grate as a whole is conserved. Furthermore, there is no danger that the lowermost layers of sintered material 15 whose burning has not yet been terminated are crushed when coming into contact with strippers and are thereby converted into abraded material. All measures for collecting, transporting and working up sintered material that has fallen through, along with abraded material, can now be dispensed with. Owing to the fact that the formation of abraded material is very much reduced the output of the total apparatus can be considerably increased. The increase of the yield of sintered material which is ready to be used in a furnace, for example sintered material with which an electrothermic phosphate reduction furnace can be charged, amounts to about 3 to 5%.

If a grate is used which yields 40 tons per hour of material ready to be used in a furnace and if the working time is utilized to an extent of 90%, that is to say if 7900 man hours are made per year which corresponds to 316,000 tons per year of sintered material ready to be used in a furnace, an increase of the yield of 3% only, results in an increase of the yield of sintered material ready to be used in a furnace of about 10,000 tons per year and, moreover, the expenditure on repair work and maintenance is reduced.

We claim:

1. An apparatus for conveying sintered material from a driven endless chain type sintering grate having a return deck and a discharge end to a driven endless chain type cooling grate having a receiving end and an up, er and a lower deck, comprising pivotally mounted grate plates supported on said chains of the sintering grate, a suction chamber positioned below said sintering grate, the return deck of the sintering grate traveling through said suction chamber, a pressure chamber positioned below said cooling grate, the receiving end of the cooling grate being supported approximately vertically below the discharge end of the sintering grate, guide ribs supported by an angle plate having a substantially horizontal leg and a substantially vertical leg arranged adjacent to the discharge end of. the sintering grate to prevent said grate plates from pivoting until they pass said guide ribs, a first inclined plane leading off from the edge of the horizontal leg of the angle plate and extending from slightly above said edge downwardly to the cooling grate and serving as a slide for the sintered material thrown off from sintering grate, a slide bar positioned adjacent and below the returning deck of the sintering grate at a point below the discharge .end of the sintering grate and serving to guide the grate plates, and a second inclined plane which is arranged outside the suction chamber below the sintering grate and below the grate plates after leaving the slide bar the lower portion of said second incline plane being positioned above the cooling grate whereby the residual portion of the sintered material falls from the freely hanging grate plates and slide therefrom onto the cooling grate.

2. An apparatus as claimed in claim 1 wherein the slide bar serving to guide the grate plate of the returning strand of the sintering grate has adjustable means connected therewith.

3. An apparatus as claimed in claim 1 wherein the substantially vertical leg of the angle plate has a bendback in the direction of the sintering grate and an open side between said substantially vertical and substantially horizontal legs, said open side facing the cooling grate.

4. An apparatus as claimed in claim 1 wherein the first inclined plane serving to convey the bulk of sintered material thrown off from the sintering grate to the cooling I grate is slanted in the direction of the upper deck of the cooling grate, and the second inclined plane which serves to convey the residual portion of the sintered material to the cooling grate is arranged above the receiving end of the cooling grate.

5. An apparatus as claimed in claim 1 which comprises driving sprockets located at the discharge end of the sintering grate and means for supplying cooling air to the grate plates as theplates pass the discharge end of the sintering grate, said means being supported within the driving sprockets.

References Cited in the file of this patent UNITED STATES PATENTS 596,494 Garretson Jan. 4, 1898 1,136,175 Sewall Apr. 20, 1915 1,786,646 Duncan Dec. 4, 1930 2,725,021 Kessler Nov. 29, 1955 2,804,834 Rivers Sept. 3, 1957 

1. AN APPARATUS FOR CONVEYING SINTERED MATERIAL FROM A DRIVEN ENDLESS CHAIN TYPE SINTERING GRATE HAVING A RETURN DECK AND A DISCHARGE END TO A DRIVEN ENDLESS CHAIN TYPE COOLING GRATE HAVING A RECEIVING END AND AN UPPER AND A LOWER DECK, COMPRISING PIVOTALLY MOUNTED GRATE PLATES SUPPORTED ON SAID CHAINS OF THE SINTERING GRATE, A SUCTION CHAMBER POSITIONED BELOW SAID SINTERING GRATE, THE RETURN DECK OF THE SINTERING GRATE TRAVELING THROUGH SAID SUCTION CHAMBER, A PRESSURE CHAMBER POSITIONED BELOW SAID COOLING GRATE, THE RECEIVING END OF THE COOLING GRATE BEING SUPPORTED APPROXIMATELY VERTICALLY BELOW THE DISCHARGE END OF THE SINTERING GRATE, GUIDE RIBS SUPPORTED BY AN ANGLE PLATE HAVING A SUBSTANTIALLY HORIZONTAL LEG AND A SUBSTANTIALLY VERTICAL LEG ARRANGED ADJACENT TO THE DISCHARGE END OF THE SINTERING GRATE TO PREVENT SAID GRATE PLATES FROM PIVOTING UNTIL THEY PASS SAID GUIDE RIBS, A FIRST INCLINED PLANE LEADING OFF FROM THE EDGE OF THE HORIZONTAL LEG OF THE ANGLE PLATE AND EXTENDING FROM SLIGHTLY ABOVE SAID EDGE DOWNWARDLY TO THE COOLING GRATE AND SERVING AS A SLIDE FOR THE SINTERED MATERIAL THROWN OFF FROM SINTERING GRATE, A SLIDE BAR POSITIONED ADJACENT AND BELOW THE RETURNING DECK OF THE SINTERING GRATE AT A POINT BELOW THE DISCHARGE 